Many speciesof tropical plants have been found to produce bioactive secondary metabolies, which may yield promising therapeutic treatments. However, in many cases very little is known about the role of these secondary compounds in the ecology of the plants producing them, and therefore much potentially useful information about the production of these compounds may be lost. An understanding of the natural functions of thee compounds, as well as the causes and patterns of vaiation in the production of these cheimcals, will help to direct the search for potentially valuable plant metabolites. This project will determine whihc species of forest plants in the Mariana Islands produce biomedically active compounds, how much variationin secondary compound production exists within plants found in the tropical forests ofthe Mariana Islands, and what sorts of environmental stresses can influence the production of these compounds. The potential causes of variation to be examined by this study are: 1) differentiallight regimes, 2) differential water availability, 3) differences among plant parts (leaves, flowers, fruits, seeds); 4) differences among old and young plant tissues; and 5) differancesin severity of herbivory. Plant parts will be collected and their secondary compounds extracted and identified. Environmental data will be gathered and compared to secondary compound production in the plants examines. Regression analysis will allow inferences to be drawn concerning the importance of environmnetal variables. Through artificial damage to plants, this study will attempt to artifically induce increased production of secondary compounds, will be analyzed for pharmacological activity. These results will be compared for evidence of stitistically significant increases in pharmacological activity.